1. Field of the Invention
The invention relates to an aerodynamic test stand.
2. Description of the Related Art
Aerodynamic test stands serve for determining aerodynamic properties, particularly in vehicles. As a rule, a wind tunnel is provided, which by means of a blower generates an airflow which is routed via straighteners to the aerodynamic test stand uniformly, in parallel and with low turbulence and noise.
It is known that, for the near-reality simulation of a road journey, it is advantageous to illustrate a moved roadway and wheel rotation, since the boundary layer flow on the ground and the flow around or through the moved wheel influence the forces acting on the vehicle. For this purpose, it has become known to arrange between the wheel rotation units, on which the vehicle is set down, a continuous runway which revolves at an appropriate speed.
DE 10 2005 040 445 A1 and DE 103 38 638 A1, furthermore, disclose a moved runway which simulates the roadway and which not only extends between the wheel rotation units, but beyond these. The vehicle is held laterally by means of fixing devices. The wheels of the vehicle are set down on standing surfaces which are located directly below the runway. The test stand shown in DE 103 638 A1 comprises a stationary floor on which the runway is mounted as an entire unit on a weighbridge. The forces in the vehicle longitudinal direction and vehicle transverse direction are measured at the bearings of the weighbridge, while the forces in the Z-direction are measured through the runway at the standing surfaces of the vehicle. It is advantageous that a road journey can be simulated optimally by means of the large-area runway. In this arrangement, however, the measurement data are influenced by aerodynamic interaction with the runway and have to be balanced accordingly.
The object of the invention is to provide an aerodynamic test stand which as accurately as possible detects the forces acting on the vehicle.